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At least 1,189 records · Page 66Linked to original sources

Worldwide occurrences of arsenic in ground water

Numerous aquifers worldwide carry soluble arsenic at concentrations greater than the World Health Organization--and U.S. Environmental Protection Agency--recommended drinking water standard of 10 mg per liter. Sources include both natural (black shales, young sediments with low flushing rates, gold mineralization, and geothermal environments) and anthropogenic (mining activities, livestock feed additives, pesticides, and arsenic trioxide wastes and stockpiles). Increased solubility and mobility of arsenic is promoted by high pH (>8.5), competing oxyanions, and reducing conditions. In this Policy Forum, Nordstrom argues that human health risks from arsenic in ground water can be minimized by incorporating hydrogeochemical knowledge into water management decisions and by more careful monitoring for arsenic in geologically high-risk areas.

Science↗

Ethyl Mercury p-Toluene Sulfonanilide: Lethal and Reproductive Effects on Pheasants

Ethyl mercury p -toluene sulfonanilide (active ingredient of Ceresan M) at a dietary concentration of 30 parts per million (12.5 parts of mercury per million) was lethal to adult ring-necked pheasants. Egg production and survival of third-week embryos were sharply reduced when breeders were maintained on feed containing 10 parts of this compound per million (4.2 parts of mercury per million).

Science↗

Geologic Settings of Subsidence

This paper reviews the role of geologic processes that contribute to subsidence in order to aid those starting investigations of ground-surface subsidence. Subsidence occurs, or at least is discovered, only infrequently, and little organized information has been available. In order to assess our present state of knowledge, the author gathered fragmentary bits of information from many sources widely scattered in the literature of geology and other earth sciences. The author cites examples for each geologic process that is a potential contributor to ground-surface subsidence together with geologic evidence for diagnosing their causes. The geologic processes involved are: (1) solution of gypsum and salt and redistribution of transient fill materials through solution cavities in calcareous rocks; (2) underground erosion of uncemented or lightly cemented silt and sand through temporary underground passageways; (3) lateral plastic flow of salt, gypsum and anhydrite, shale, and clay under loading; (4) compaction of sediments by loading, drainage, vibration, and hydrocompaction; (5) tectonic movements including primary and secondary effects of earthquakes, folding, and warping; and (6) volcanic activity. Because the first four processes may be accelerated by various engineering activities, examples have been selected to illustrate subsidence both under natural conditions and under conditions modified by man's activities. Although this extensive search for existing information on the role of geologic factors in subsidence indicates that much detailed work remains to be done, the future prospects for advancing our geologic knowledge are excellent. Methods of measuring ground-surface displacements are improving rapidly. Also, broadly based investigations of known areas of major subsidence throughout the world are developing new methods of diagnosis and treatment and are yielding quantitative data that will aid our evaluation of the rates and magnitude of present-day geologic processes.

Book chapter↗

Physiological and endocrine changes in Atlantic salmon smolts during hatchery rearing, downstream migration and ocean entry

Billions of hatchery salmon smolts are released annually in an attempt to mitigate anthropogenic impacts on freshwater habitats, often with limited success. Mortality of wild and hatchery fish is high during downstream and early ocean migration. To understand changes that occur during migration, we examined physiological and endocrine changes in Atlantic salmon (Salmo salar) smolts during hatchery rearing, downstream migration, and early ocean entry in two successive years. Gill Na + /K + -ATPase activity increased in the hatchery during spring, increased further after river release, and was slightly lower after recapture in the ocean. Plasma growth hormone levels increased in the hatchery, were higher in the river, and increased further in the ocean. Plasma IGF-I remained relatively constant in the hatchery, increased in the river, then decreased in the ocean. Plasma thyroid hormones were variable in the hatchery, but increased in both river- and ocean-captured smolts. Naturally reared fish had lower condition factor, gill NKA activity, and plasma thyroxine than hatchery fish in the river but were similar in the ocean. This novel data set provides a vital first step in understanding the role and norms of endocrine function in smolts and the metrics of successful marine entry.

Maine↗

Pre-restoration woody species crown and vegetation community mapping using high-resolution uncrewed aerial system imagery, Palmyra Atoll

The terrestrial management plan for Palmyra Atoll includes large-scale removal of coconut ( Cocos nucifera ) as part of native forest restoration and contaminant remediation that will leave soils and vegetation communities profoundly altered. To inform those efforts and provide baseline data for restoration monitoring, woody stem crowns and vegetation communities at Palmyra Atoll were mapped using existing datasets and manual photointerpretation of high-resolution aerial imagery collected using uncrewed aerial systems. Coconut palm, grand devil's claws ( Pisonia grandis ), and numerous other species were delineated as either individual crowns, crown portions, or species patches. The extent of land area at high tide was also delineated based on vegetation patterns, topographic indicators, and deposition lines of vegetation litter and flotsam. Finally, in a novel “bottom-up” approach to vegetation community mapping, crown maps were used to delineate U.S. National Vegetation Classification System vegetation communities and other management areas. Of the more than 44,000 mapped crowns, coconut was by far the most abundant species, comprising nearly half of the mapped stems. By establishing a quantitative baseline for current habitat conditions, this project facilitates the integration of contaminant remediation recovery activities with habitat restoration planning, implementation, and monitoring at Palmyra Atoll. Results illustrate the appropriateness of the mapping approach for plant species-level censuses and cover estimation over relatively small areas to aid in inventory and monitoring and to facilitate management planning. The relatively simple mapping methods used in this study are appropriate for resource managers with limited human and computational resources to support automated mapping.

Pacific Science↗

Towards policy relevant environmental modeling: contextual validity and pragmatic models

"What makes for a good model?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of modeling. One particular domain that is wrestling with this question is the multidisciplinary field of environmental modeling. Examples of environmental models range from models of contaminated ground water flow to the economic impact of natural disasters, such as earthquakes. One of the distinguishing claims of the field is the relevancy of environmental modeling to policy and environment-related decision-making in general. A pervasive view by both scientists and decision-makers is that a "good" model is one that is an accurate predictor. Thus, determining whether a model is "accurate" or "correct" is done by comparing model output to empirical observations. The expected outcome of this process, usually referred to as "validation" or "ground truthing," is a stamp on the model in question of "valid" or "not valid" that serves to indicate whether or not the model will be reliable before it is put into service in a decision-making context. In this paper, I begin by elaborating on the prevailing view of model validation and why this view must change. Drawing from concepts coming out of the studies of science and technology, I go on to propose a contextual view of validity that can overcome the problems associated with "ground truthing" models as an indicator of model goodness. The problem of how we talk about and determine model validity has much to do about how we perceive the utility of environmental models. In the remainder of the paper, I argue that we should adopt ideas of pragmatism in judging what makes for a good model and, in turn, developing good models. From such a perspective of model goodness, good environmental models should facilitate communication, convey—not bury or "eliminate"—uncertainties, and, thus, afford the active building of consensus decisions, instead of promoting passive or self-righteous decisions.

Open-File Report↗

Documenting the multiple facets of a subsiding landscape from coastal cities and wetlands to the continental shelf

Land subsidence is a settling, sinking, or collapse of the land surface. In the southeastern United States, subsidence is frequently observed as sinkhole collapse in karst environments, wetland degradation and loss in coastal and other low-lying areas, and inundation of coastal urban communities. Human activities such as fluid extraction, mining, and overburden alteration can cause or exacerbate subsidence, which can result in damage to infrastructure and resources. Subsidence is a hazard that takes place throughout the United States; however, a systematic approach to recognize and develop informed responses to the drivers of subsidence has not yet been fully established. To address this problem, the U.S. Geological Survey (USGS) Southeast Region (SER) funded the gathering of a team of interdisciplinary USGS scientists to promote scientific collaboration. Southeast Region scientists welcomed scientists from other regions (see table 1.1 in Appendix 1) in September 2018 at the St. Petersburg Coastal and Marine Science Center (SPCMSC) in Florida for the first workshop of the Subsidence Flex Team (SFT) (see Appendix 2 for agenda). The SFT set out to review subsidence-related research and technology and develop a unifying framework for describing the processes and hazards associated with land subsidence. A more comprehensive understanding of subsidence hazards could help to inform regional vulnerability assessments that would prove invaluable to the public, community developers, policy makers, and resource managers in both inland and coastal states. The SFT analyzed USGS strengths and weaknesses to identify existing infrastructure and capabilities that could be leveraged to create a comprehensive and far-reaching subsidence-monitoring and mitigation program. Over the course of the 2-day workshop, interdisciplinary understandings of the processes and hazards related to subsidence were explored through individual presentations and group discussion. With all perspectives considered, the SFT recommended that subsidence-related research develop scientific approaches and metrics by which the subsidence component can be isolated and quantified in order to protect both the environment and human infrastructure from harm.

Alabama, Florida, Louisiana, Mississippi↗

Influence of repeated prescribed fire on tree growth and mortality in Pinus resinosa forests, northern Minnesota

Prescribed fire is widely used for ecological restoration and fuel reduction in fire-dependent ecosystems, most of which are also prone to drought. Despite the importance of drought in fire-adapted forests, little is known about cumulative effects of repeated prescribed burning on tree growth and related response to drought. Using dendrochronological data in red pine ( Pinus resinosa Ait.)-dominated forests in northern Minnesota, USA, we examined growth responses before and after understory prescribed fires between 1960 and 1970, to assess whether repeated burning influences growth responses of overstory trees and vulnerability of overstory tree growth to drought. We found no difference in tree-level growth vulnerability to drought, expressed as growth resistance, resilience, and recovery, between areas receiving prescribed fire treatments and untreated forests. Annual mortality rates during the period of active burning were also low (less than 2%) in all treatments. These findings indicate that prescribed fire can be effectively integrated into management plans and climate change adaptation strategies for red pine forest ecosystems without significant short- or long-term negative consequences for growth or mortality rates of overstory trees.

Minnesota↗

Topographic data requirements for EOS global change research

This document is a result of Earth Observing System Data and Information System (EOSDIS) Version 0 activities of the Land Processes Distributed Active Archive Center at the U.S. Geological Survey's EROS Data Center. A relatively small part of the Version 0 funding provided by NASA is used to address topographic data issues related to EOS. These issues include identifying and improving access to existing sources of topographic data, data generation, facilitating the use of topographic data in global change research by demonstrating derivative products, and inventorying the specific topographic data requirements of EOS investigators. There is a clear need for global topographic data in EOSDIS. Only 10 percent of the global land surface is covered by high-resolution data that are available to the global change science community. Alternative sources for new data exist or have been proposed; however, none of them alone can fulfill the data requirements by the launch of the first EOS platform in 4 years. There is no operational provider of all the source data that are required. Even if appropriate global source data existed, a concerted production effort would be necessary to ensure the existence of the requisite topographic data before EOS launch. Additionally, no funding from NASA or any other agency has been appropriated for a new mapping mission or for other means of data acquisition. This effort to document requirements is an initial step toward understanding the severity of the data shortage. It is well beyond the scope of Version 0 funding and capabilities to provide the required data in the proper timeframe. The shortage of data and the lack of a plan for providing the necessary topographic data through EOSDIS in time for launch are issues that must be addressed by the EOS program.

Open-File Report↗

PRMS-IV, the precipitation-runoff modeling system, version 4

Computer models that simulate the hydrologic cycle at a watershed scale facilitate assessment of variability in climate, biota, geology, and human activities on water availability and flow. This report describes an updated version of the Precipitation-Runoff Modeling System. The Precipitation-Runoff Modeling System is a deterministic, distributed-parameter, physical-process-based modeling system developed to evaluate the response of various combinations of climate and land use on streamflow and general watershed hydrology. Several new model components were developed, and all existing components were updated, to enhance performance and supportability. This report describes the history, application, concepts, organization, and mathematical formulation of the Precipitation-Runoff Modeling System and its model components. This updated version provides improvements in (1) system flexibility for integrated science, (2) verification of conservation of water during simulation, (3) methods for spatial distribution of climate boundary conditions, and (4) methods for simulation of soil-water flow and storage.

Techniques and Methods↗

Windows to the deep 2018: Exploration of the southeast US Continental margin

Windows to the Deep 2018: Exploration of the Southeast US Continental Margin was a 36-day expedition aboard NOAA Ship Okeanos Explorer to acquire data on priority exploration areas identified by the ocean management and scientific communities. This expedition involved high-resolution multibeam sonar mapping and ROV dives, ranging from 340 m to 3,400 m depth, across the southeast US continental margin. Operations primarily targeted areas with potential to host deep-sea coral and sponge communities, including mounds, ridges, and terraced features on the continental slope. Dive sites also included maritime heritage sites, a submarine landslide feature, and several submarine canyon slopes, some of which exhibited evidence of active cold seeps. High biological abundance was noted at six of 17 dive sites, three of which also had high biological diversity. Additionally, deep-sea corals or sponges were observed on every dive except one, which was dedicated to gas seep exploration.

Atlantic Ocean, Blake Plateau, Stetson Mesa↗

Fisheries research and monitoring activities of the Lake Erie Biological Station, 2024

A comprehensive understanding of fish populations and their interactions is the cornerstone of modern fishery management and the basis for Lake Erie’s Fish Community Objectives (FCOs) developed in 2020 (Francis et al. 2020). The 2024 U.S. Geological Survey (USGS) Lake Erie Biological Station Annual Report is responsive to these FCOs and the USGS obligations via a Memorandum of Understanding (MOU 2017) with the Great Lakes Fishery Commission (GLFC) Council of Lake Committees (CLC) to provide scientific information in support of fishery management. Goals for the USGS Great Lakes Deepwater Fish Assessment and Ecological Studies were to monitor long-term changes in the fish community and track population dynamics of key fishes of interest to management agencies. Specific to Lake Erie, expectations were sustained investigations of native percids, prey fish populations, and Lake Trout. All work was conducted as part of the Deepwater Science Program under the authority of the Great Lakes Fishery Research Authorization Act of 2019 (16 USC §941h). The USGS 2024 Deepwater Science Program fieldwork began in Lake Erie in March and concluded in December, using trawl, gill net, hydroacoustic, lower trophic sampling devices, and telemetry methods. This work resulted in 44 bottom trawls covering 41 ha of lake bottom and catching 48,936 fish totaling 995 kg in the West Basin of Lake Erie, with detailed results described below. Overnight gill net sets (n=25) for coldwater species were performed in the East Basin of Lake Erie. A total of 8 km of gillnet was deployed during these surveys, which caught 106 fish, 92 of which were native coldwater species: Lake Trout, Burbot, and Lake Whitefish. Results from coldwater species assessments will be reported in the Coldwater Task Group report to the GLFC and the CLC (CTG 2025). These reports are used to inform Lake Trout stocking decisions and direct lamprey control measures (16 USC §939a). USGS hydroacoustic sampling included twenty-six 5-km transects (130 km total) in the Central Basin as part of a collaborative lake-wide survey with details and results reported by the Forage Task Group (FTG 2025). Lower trophic sampling provided data from zooplankton samples (n=12) and water quality profiles (n=12) to populate a database maintained by the Michigan Department of Natural Resources (MDNR), Ontario Ministry of Natural Resources (OMNR), Ohio Department of Natural Resources (ODNR), Pennsylvania Fish and Boat Commission (PFBC), and New York State Department of Environmental Conservation (NYSDEC). USGS also assisted CLC member agencies with deployment and maintenance of Great Lakes Acoustic Telemetry Observation System (GLATOS) infrastructure throughout all three Lake Erie basins and tributaries, supporting multiple coordinated telemetry investigations. This report presents biomass-based summaries of fish communities in western Lake Erie derived from USGS bottom trawl surveys conducted from 2013 to 2024 during June and September. The survey design compliments the August ODNR- OMNRF effort by reinforcing stock assessments with more robust data. Analyses herein evaluated trends in total biomass, abundance of dominant predator and forage species, non-native species composition, biodiversity, and community structure. Data from this effort are accessible for download (Keretz et al. 2025)

Lake Erie↗

Was Himalayan normal faulting triggered by initiation of the Ramgarh-Munsiari Thrust?

The Ramgarh–Munsiari thrust is a major orogen-scale fault that extends for more than 1,500 km along strike in the Himalayan fold-thrust belt. The fault can be traced along the Himalayan arc from Himachal Pradesh, India, in the west to eastern Bhutan. The fault is located within the Lesser Himalayan tectonostratigraphic zone, and it translated Paleoproterozoic Lesser Himalayan rocks more than 100 km toward the foreland. The Ramgarh–Munsiari thrust is always located in the proximal footwall of the Main Central thrust. Northern exposures (toward the hinterland) of the thrust sheet occur in the footwall of the Main Central thrust at the base of the high Himalaya, and southern exposures (toward the foreland) occur between the Main Boundary thrust and Greater Himalayan klippen. Although the metamorphic grade of rocks within the Ramgarh–Munsiari thrust sheet is not significantly different from that of Greater Himalayan rock in the hanging wall of the overlying Main Central thrust sheet, the tectonostratigraphic origin of the two different thrust sheets is markedly different. The Ramgarh–Munsiari thrust became active in early Miocene time and acted as the roof thrust for a duplex system within Lesser Himalayan rocks. The process of slip transfer from the Main Central thrust to the Ramgarh–Munsiari thrust in early Miocene time and subsequent development of the Lesser Himalayan duplex may have played a role in triggering normal faulting along the South Tibetan Detachment system.

International Journal of Earth Sciences↗

Temporal evaluation of estrogenic endocrine disruption markers in smallmouth bass (Micropterus dolomieu) reveals seasonal variability in intersex

A reconnaissance project completed in 2009 identified intersex and elevated plasma vitellogenin in male smallmouth bass inhabiting the Missisquoi River, VT. In an attempt to identify the presence and seasonality of putative endocrine disrupting chemicals or other factors associated with these observations, a comprehensive reevaluation was conducted between September 2012 and June 2014. Here, we collected smallmouth bass from three physically partitioned reaches along the river to measure biomarkers of estrogenic endocrine disruption in smallmouth bass. In addition, polar organic chemical integrative samples (POCIS) were deployed to identify specific chemicals associated with biological observations. We did not observe biological differences across reaches indicating the absence of clear point source contributions to the observation of intersex. Interestingly, intersex prevalence and severity decreased in a stepwise manner over the timespan of the project. Intersex decreased from 92.8% to 28.1%. The only significant predictor of intersex prevalence was year of capture, based on logistic regression analysis. The mixed model of fish length and year-of-capture best predicted intersex severity. Intersex severity was also significantly different across late summer and early spring collections indicating seasonal changes in this metric. Plasma vitellogenin and liver vitellogenin Aa transcript abundance in males did not indicate exposure to estrogenic endocrine disrupting chemicals at any of the four sample collections. Analysis of chemicals captured by the POCIS as well as results of screening discrete water samples or POCIS extracts did not indicate the contribution of appreciable estrogenic chemicals. It is possible that unreported changes in land-use activity have ameliorated the problem, and our observations indicate recovery. Regardless, this work clearly emphasizes that single, snap shot sampling for intersex may not yield representative data given that the manifestation of this condition within a population can change dramatically over time.

Vermont↗

Diving deeper into seep distribution along the Cascadia Convergent Margin, USA

Previous margin-wide studies of methane seep distribution along the Cascadia Subduction Zone indicate peaks in seep density within the landward limit of the of gas hydrate stability zone (GHSZ; ≤500 m depth), suggesting a link between current ocean warming, acceleration of hydrate dissociated, and methane emissions. This inferred connection, however, may not account for regional geologic and/or structural complexities driving methane seepage. Expanding upon an existing seep database by adding new seeps data, we conducted statistical and spatial analyses to determine margin-wide distribution trends and offer a tectonic framework for understanding the tendency toward non-normality and spatial clustering. We then highlight the role of local-scale drivers of seep formation in addition to the first-order tectonic framework, using systematic geologic/geomorphic characterization of seep emission sites in southern Cascadia and case studies using meta-attribute analysis of seismic reflection data.. Seep distribution along the margin is non-random, but instead of clustering along the 500-m isobath, regions of high seep density occur in canyons and topographic highs. New findings from this study conclude that co-location of the outer arc high (OAH) and the landward limit of the GHSZ may explain high concentrations of seeps where deformation is the greatest and hydrates are unstable. Detailed analysis of the spatial relationships between seep sites and geologic-geomorphic features in southern Cascadia reveal a link between seeps and anticlines, with 52% of the seeps found in association with anticlines, 36% found at faults, 16% associated with canyons, and 11% at seafloor failure scarps. Given that a majority of anticlines are located along or seaward of the OAH in the actively deforming outer wedge, we suggest that the location of the OAH is a primary structural control on seep distribution. This scenario is supported by neural network analysis of multichannel seismic data revealing zones of probable fluid migration along vertical pipes, faults, and chimneys in the vicinity of active seep sites on anticlines. Determining linkages between seeps and submarine tectonic geomorphology is a crucial first step for understanding and forecasting the distribution of methane seepage, but also a necessity for evaluating causal relationships between ocean warming and gas-hydrate stability.

California, Oregon, Washington↗

Coastal erosion and wetland change in Louisiana: selected USGS products

This Digital Data Series (DDS) report is primarily a selection of USGS science products that were previously published as paper atlases and maps but are no longer available in their original form. We have made an attempt to preserve the paper atlases by having them scanned in an efficient compressed digital format that provides a print-on-demand as well as a programmed viewing capability of the original material. We included additional materials bearing on aspects to enhance the scientific understanding of coastal erosion and wetland loss in Louisiana. In addition, this report contains multimedia-based publications including photographs, a 48-minute video, and map tools to allow the user to experience the many scientifically based research activities that are in progress along the coast of Louisiana.

Data Series↗

Proceedings of the 2024 Asia-Pacific Wildlife Health Workshop—Collaborating against shared threats

Emerging diseases of wildlife origin are increasingly transboundary (they spread rapidly across geographic regions and across continents). In recent years, examples include the rapid spread of African swine fever across Europe and Asia with negative effects on food security, and the near global spread of highly pathogenic avian influenza which has devastated wildlife populations, caused economic harm, and which threatens public health; consequently, international partnerships and networks are essential to facilitate the sharing of information for improved situational awareness and better preparedness and response. In this regard, the U.S. Geological Survey and the Korea National Institute for Wildlife Disease Control and Prevention have had a long-standing partnership to foster scientific collaboration. A key part of the activities has been annual scientific workshops, which commenced in 2016. The 2024 workshop in Hilo, Hawaii, was the most recent in these series of workshops and included participants from across Asia and the Pacific region, including Thailand, Vietnam, China, Republic of Korea, Japan, Australia, Cook Islands, Fiji, and the United States. The goals of the workshop were: to continue to build the wildlife health community of practice in the Asia-Pacific region and expand the participants to agencies and institutions from other countries in the region; and exchange scientific knowledge among the participants to share best practices, create scientific networks, and build capacity in wildlife health science for the Asia-Pacific region. The themes discussed at the workshop included wildlife health risk management, avian Influenza, African swine fever, climate change and emerging diseases, and international cooperation. This report contains the author-submitted abstracts which provide a summary of the presentations and discussions during the workshop. The aim is to share this information to continue to foster international scientific exchange to protect wildlife health, livestock, and public health from the negative impacts of infectious and noninfectious diseases.

Open-File Report↗

The Hawaiian Volcanoes Supersite: Open data for the benefit of science and society

The Hawaiian Volcanoes Supersite was established in 2008 with the goal of making large amounts of volcano monitoring data, especially satellite measurements, freely available at a site of international interest, scientific importance, and impactful natural hazards. The location was chosen because of the long history of volcanological research and innovation on the Island of Hawaiʻi, as well as the need for monitoring, assessing, and mitigating volcanic hazards for the local population. Ground-based data are provided by the U.S. Geological Survey Hawaiian Volcano Observatory, and several national space agencies have contributed thousands of satellite synthetic aperture radar and other data that would have otherwise required special grants or commercial purchase. Since the Hawaiian Volcanoes Supersite was initiated, the vast quantity of open space-based data has resulted in the development of new applications and methodologies, successful responses to volcanic crises, and research that has informed monitoring and hazards mitigation activities. While there remain opportunities for additional coordination among supersite users and for synergistic studies that make use of the full spectrum of available ground- and space-based data, the Hawaiian Volcanoes Supersite has achieved its goals of stimulating basic research to better understand Hawaiian volcanism and aiding in responses to hazardous geologic processes. The effort serves as a model for the benefits of open, low-latency, and comprehensive satellite data applied to disaster risk management and reduction, meeting a vision that has been laid out repeatedly in international agreements and accords.

Hawaii↗